Drilling Bit Core Evacuation Cavity Design

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Solution Overview

Problem

Existing drilling bits for deep wells face clogging issues when encountering soft rocks, leading to significant time losses as they require frequent cleaning or core evacuation, making them unsuitable for drilling through varied geological formations.

Innovation Solution

A drilling bit with radial blades and a central core evacuation system, featuring a cavity between blades for core evacuation and a breaking device made of abrasion-resistant material to shear the core, preventing clogging and allowing continuous drilling through all types of rocks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a bit with diamonds array is used to drill hard rocks, then drilling efficiency is improved, but the spaces between diamonds become clogged when soft rock is encountered, causing the tool to stop working

Engineering Contradiction:

Improvedrilling efficiencyVSAvoidcontinuous operation capability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The bit is divided into multiple functional zones: an external annular crown with blades for drilling hard rocks, and a central zone with a core for handling soft rock formations. This segmentation allows each zone to specialize in different rock types, preventing clogging issues that affect the entire tool.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of having the entire bit surface active for drilling, the invention inverts the approach by creating a central core space that is deliberately left empty to receive and evacuate soft rock cuttings. This inversion transforms the potential clogging problem into a functional feature for handling varied geology.

Inventive Principle:

Principle #13The other way round (Inversion)

2Productivity

If a crushing chamber is added to break the core, then core evacuation is improved, but the crushing chamber becomes clogged when soft rock is encountered, requiring bit removal for cleaning and causing time loss

Engineering Contradiction:

Improvecore evacuation efficiencyVSAvoidbit removal and cleaning time

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The core is extracted from the drilling process and placed in a separate central zone rather than being processed within the main drilling structure. This extraction allows the core to be evacuated separately through dedicated channels, preventing it from clogging the main crushing chamber and blade areas.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

A dedicated core evacuation channel acts as an intermediary pathway between the core space and the external environment. This mediator channel allows soft rock cuttings to be removed efficiently without entering and clogging the crushing chamber or blade assembly.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of operation

If the central zone of the bit is used to destroy the core periodically, then core removal is achieved, but the central zone becomes clogged when soft rock is encountered, requiring bit removal for cleaning and causing considerable time loss

Engineering Contradiction:

Improvecore destruction capabilityVSAvoidbit removal and cleaning time

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The core evacuation process is made continuous through dedicated channels that constantly remove cuttings from the core space. This continuous action prevents clogging in the central zone, eliminating the need for periodic bit removal and cleaning operations.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

Drilling fluid circulation is used to continuously flush and evacuate core material from the central zone through dedicated channels. This hydraulic action prevents clogging and maintains continuous operation without requiring bit removal for cleaning.

Inventive Principle:

Principle #29Pneumatics and hydraulics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables rapid drilling of deep wells without clogging by efficiently evacuating and breaking the core, facilitating the analysis of petrophysical properties and maintaining stability during drilling.

Implementation Method 1

a breaking device made of abrasion-resistant material to shear the core

Methodology Applied

Scientific EffectAbrasion: Abrasion

Data Source

PatentUS8960335B2Bit for drilling wells and associated drilling method

Publication Date: 2015.02.24 DIAMANT DRILLING SERVICES

AI summary

A bit for drilling wells has a front face with radial blades having cutting elements distributed around the front face. A space for forming a core is situated at the center of the front face. A cavity is provided for evacuating the core towards a periphery of the bit. At least a portion of the cavity is situated between adjacent blades. The cavity is delimited by two lateral surfaces and a clearance surface set back with respect to the front face, and the cavity is open in a direction opposite the clearance surface. The bit may be used in methods for drilling wells and makes it possible to rapidly drill wells of great depth in all types of rock without the risk of clogging.